Anguilla, Antigua And Barbuda, Aruba, Bahamas, Barbados, Belize, Canada, Cayman Islands, Colombia, Costa Rica, Cuba, Dominica, Dominican Republic, El Salvador, Guadeloupe, Guatemala, Haiti, Honduras, Martinique, Mexico, Montserrat, Netherlands Antilles, Nicaragua, Panama, Puerto Rico, St Kitts And Nevis, St Lucia, St Vincent and The Grenadines, Turks and Caicos Islands, USA (B), Venezuela, Virgin Islands (British) (P), Virgin Islands (U.S.) (P).
Vagrant to Jamaica.
Breeds in eastern USA from southern Wisconsin, south-eastern Minnesota, eastern Kansas and eastern Texas east to New Jersey, south to central Louisiana, north-western Florida and eastern Georgia. Migrates to wintering grounds from eastern and southern Mexico south to Panama, also irregularly in adjacent northern Colombia and northern Venezuela.
Population
Estimated population is 1,100,000 (2010).
Kentucky Warbler (Geothlypis formosa) [XC368060]
by Eric DeFonso from Mississippi Palisades State Park (near Savanna), Carroll, Illinois, United States (song)
Kentucky Warbler (Geothlypis formosa) [XC827878]
by Richard E. Webster from McCormack Lake, Mark Twain NF, MO, United States (call)
Subspecies
No subspecies.
Genus sometimes subsumed in Geothlypis. This species is very similar, both in plumage and, according to one study, genetically, to Olive-crowned Yellowthroat (Geothlypis semiflava) and possibly forms a link between the two genera. Has hybridized with Blue-winged Warbler (Vermivora cyanoptera) (hybrid originally described as a new species, Helminthophaga cincinnatiensis). One of the two specimens of this pairing originally thought to have involved Mourning Warbler (Geothlypis philadelphia), rather than present species. Recent record of hybridization with Mourning Warbler (Geothlypis philadelphia). Birds in north of breeding range described as subspecies umbraticus, apparently paler yellow below and more yellowish-olive on upperparts, but inadequately differentiated from birds in rest of species' range.
BirdLife International Species Factsheet